I have to say this beta has been the buggiest, Too many to list but I will point to...
1- apps constantly crash and just shut down but appear to be still running
2- mail, loading mail show no messages, but will after a force quit. also when scrolling through mail it doesnt show any messages. when searching it will initially show results but then they dont display
there are a bunch more issues(I know it's a beta) but it seems many more than even beta 1